> I reran the tests with hashtext(), and created a SUMMARY.HTML chart: > > http://momjian.us/expire/TOAST/ > > What you will see is that pushing TEXT to a TOAST column > allows quick access to non-TOAST values and single-row TOAST > values, but accessing all TOAST columns is slower than > accessing them in the heap, by a factor of 3-18x.
Um, my understanding for this measurement would be to tweak TOAST_TUPLE_THRESHOLD, and use a fixed TOAST_MAX_CHUNK_SIZE ? Why would you want to increase the number of toast tuples required for one column value ? My expectation would be, that we want to allow a toast tuple to fill a whole page (TOAST_TUPLES_PER_PAGE = 1), but keep or reduce the threshold. Maybe we need other logic to find and use free space for that, though (8.4 material). Andreas ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate